It is well known that item prices are often changed for various reasons in many retail shops such as supermarkets. For instance, some foods are often discounted unless sold out in short periods of time, because such foods are likely to lose their value. There are also a number of cases in which some designated items are sold at bargain prices during certain intervals during a day.
For this puropose, heretofore, some ECRs have been provided with PLU tables where item prices are changeably stored, while others have been provided with PLU tables storing a plurality of prices with respect to each item so that the item prices are changeable by selecting one of the stored prices.
The ECRs described above, however, have the following disadvantages:
1. In the former type, operation of the ECRs must be temporarily stopped each time there is a need for changing the prices stored in the PLU tables, so that the operation efficiency is lowered.
2. In the latter type, each item is required to hold its corresponding price because all the prices are changed at one time irrespective of items, so that extra memory location is required with respect to even such items which are not incurring a change in price.